JP2006-510849A (U.S.2006-0226263A1, DE10325289A1, CN1798920A) discloses a fuel injector, in particular for a direct injection of fuel into a combustion chamber of an internal combustion engine. The fuel injector has a valve-closure member which cooperates with a valve-seat surface formed on a valve-seat body, to form a sealing seat. The fuel injector includes at least one spray-discharge orifice provided downstream from the sealing seat. The spray-discharge orifice has a guide region and an exit region arranged at its discharge-side end. The exit region widens in a stepped manner by at least one first step and/or at least in part continuously beginning with a transition from the guide region into the exit region. A fuel jet which emerges from the guide region at the transition and widens essentially uniformly at a jet angle, passes a discharge-side end of the exit region with a gap dimension of a gap after a distance. The gap dimension is greater than zero and a first volume remaining in the exit region between the fuel jet and the inner walls of the exit region.
In the conventional fuel injector, when a pressure of a fuel spray is lower than a specified value, the fuel spray is formed to suppress a caulking. However, when a pressure of a fuel spray is higher than the specified value, the fuel spray is attracted to an inner wall surface of the injector body. The fuel may adhere to the inner wall surface.